stable_partition

This is a discussion on stable_partition within the C++ Programming forums, part of the General Programming Boards category; hi,
i have a vector of vectors representing a set of d-dimensional points.
Code:
vector < vector <int> > points
...

stable_partition

i have a vector of vectors representing a set of d-dimensional points.

Code:

vector < vector <int> > points

I want to use the stl algorithm stable_partition to partition the set according to the values in a dimension. For example

if my set of 3-d points is:
0 2 0 ---> every row is a vector of the same size representing a point (3d here)
9 3 3
1 8 4
1 7 5
3 4 6
I want to partition it into two parts (less/greater than a given value, or using the median), using a given dimension.
Say, if want to partition in the 3rd dimension according to the value 3, then
partition 1 would be
0 2 0
9 3 3
and partition 2
1 8 4
1 7 5
3 4 6
Of course, I should be able to partition according to any given dimension at a time (I could do it later by the 2nd or the 1st).
I am a bit confused of how the predicate for such a function would be.